While President
Lincoln promised to uphold the Emancipation Proclamation and
other wartime emancipation measures, Congress took steps to
ensure that the institution of slavery was abolished permanently
in all the states. In order to make certain that future
enslavement did not occur and to protect emancipation from
modification or nullification by any president, Congress,
Supreme Court, or state government, advocates of abolition
concluded that a constitutional amendment was necessary.

Amending the U.S. Constitution was an
uncommon occurrence. The then-current twelve amendments had all
been adopted within the first 15 years of the republic operating
under the Constitution: the first ten—the Bill of Rights—were
ratified in 1791, the Eleventh in 1795, and the Twelfth in
1804. In the Antebellum Era (the decades before the Civil War),
several amendments protecting slavery were proposed, but very
few were suggested for abolishing the institution. Many
Antebellum Americans on both sides of the slavery question
revered the Constitution as it was and saw only the need to
interpret it correctly (however they defined that), not to
change it. The secession crisis of December 1860–March 1861
finally prompted Americans to consider more seriously the
amendment option. However, as in the Antebellum Era, virtually
all of the proposals during the secession crisis
protected slavery.

The Civil War gradually increased the
percentage of white Northerners who favored abolition, whether
as an act of military necessity, revenge on the South, or moral
justice. On December 14, 1863, Congressman James Ashley,
Republican of Ohio, introduced a bill in support of a
constitutional amendment to prohibit slavery in the entire
United States. It was the first antislavery amendment proposed
by a congressman since John Quincy Adams in 1839. Soon after,
Congressman James Wilson, Republican of Iowa, introduced a
similar proposal to end slavery by constitutional amendment. At
first, there was little press attention to the issue, even
though there was a popular surge in various organizations
petitioning Congress in the winter of 1863-1864 favoring some
type of abolition amendment. Congressional actions detailed
each week in the “Domestic Intelligence” column of Harper’s
Weekly contained references to petitions for
abolishing slavery nationwide, but did not mention either
Ashley’s or Wilson’s proposed abolition amendment.

Although opposition to slavery was
associated with the Republican Party, a faction of War Democrats
not only supported wartime emancipation policies but also became
favorable to a constitutional amendment abolishing the
institution. On January 11, 1864, Senator John Henderson of
Missouri, a War Democrat, submitted a joint resolution for a constitutional amendment abolishing slavery. The
Senate Judiciary Committee, headed by Illinois Republican Lyman
Trumbull, began considering the various versions of the
abolition amendment. On February 8, Senator Charles Sumner of
Massachusetts, a leading Radical Republican, submitted a
constitutional amendment to not only abolish slavery but also
guarantee equality under the law. Two days later, spurred
partly in reaction to Sumner’s more radical proposal, the Senate
Judiciary Committee reported to the full Senate an abolition
amendment combining the drafts by Ashley,
Wilson, and Henderson.

In the February 27, 1864 issue of
Harper’s Weekly (published February 17), editor George
William Curtis argued that had Senator Stephen
Douglas lived, he would have endorsed amending the Constitution
to abolish slavery. Douglas had authored the
Kansas-Nebraska
Act of 1854, which had opened the Western
territories to slavery, and he had been the presidential nominee
of the Northern wing of the Democratic Party in 1860. He had
strongly opposed secession and backed the Union once the Civil
War began. He died on June 3, 1861. The last paragraphs of the
editorial harshly criticized Peace Democrats, such as Clement
Vallandigham and Fernando Wood, who advocated a truce and
negotiated settlement with the Confederacy.

In fact, in mid- and late-February, the
proposed Thirteenth Amendment was endorsed by some prominent War
Democrats, including New York Herald publisher James
Gordon Bennett Sr., who called for the Democratic Party to
embark on a “new departure” by shedding its pro-slavery image;
Senator Reverdy Johnson of Maryland, a former U.S. Attorney
General; and, as expected, Senator John Henderson of Missouri,
whose own draft had influenced the final committee version. It
was the respected Reverdy Johnson’s endorsement that first made
the press begin paying closer attention to the proposed
abolition amendment. On February 18, Congressman James Brooks
of New York became the first notable Peace Democrat to back the
Thirteenth Amendment (although he later changed his position and
opposed it by the end of the year).

In the March 12, 1864 issue (published
March 2), editor Curtis agreed with Brooks’s
conclusion that slavery must be ended. The Harper’s Weekly
commentary listed euphemisms used to avoid the word
“slavery” and hide the cruelty of the institution. Such polite
but misleading expressions included “persons held in labor,”
“involuntary servitude,” and, in a recent joint resolution of
the Confederate Congress, “the selected type of social
characteristics.” Curtis combined the euphemism of “selected
type” and Brooks’s remark that slavery had been “thrown into pi”
for the clever title of his editorial, “Type in Pi.” The title
and Brooks’s phrase both referred to printing jargon for being
or becoming jumbled, confused, or chaotic.

Not only were some Democrats becoming
favorable toward abolition, but public sentiment in the Border
States was also moving in that direction. In January 1864,
Senator Henderson of Missouri had proposed his federal abolition
amendment; in February, the Maryland electorate voted to hold a state convention for drafting an antislavery
constitution; and in March, voters in the new state of West
Virginia approved a constitution granting gradual emancipation
there.

Nevertheless, a few Republicans and a
majority of Democrats in the U.S. House remained unconvinced of
the worth of an abolition amendment. On February 15, 1864, the
first House vote on the proposed Thirteenth
Amendment fell far short of the necessary two-thirds majority,
78-62. Only 1 Democrat voted for it and 52 were opposed, while
only 2 Republicans voted against it and 66 were in favor.
Congressmen independent of the two major parties fell into two
groups—Union and Unconditional Union. The Unconditional Union
men voted 10-1 in favor of the proposed Thirteenth Amendment,
while the Union men were 7-1 against.

On March 28, a substitute abolition
amendment sponsored by Congress Thaddeus
Stevens of Pennsylvania, a dedicated abolitionist and leading
radical Republican, also fell short of a two-thirds majority.
Its language reflected that of the Thirteenth Amendment, but
added a section explicitly nullifying the fugitive slave clause
of the Constitution. An attempt to remove the fugitive slave
clause portion and revote on the abolitionist amendment was
interrupted by news of the death of a fellow congressman. An
editorial in the April 9, 1864 issue of
Harper’s Weekly praised a loyal Democratic state legislator
in New York for endorsing a federal abolition amendment, but
criticized five Democratic congressmen from New York who voted
against Stevens’s version. Editor George William Curtis
wondered “Under Which” policy—freedom or slavery—the Democratic
Party would rally.

On April 8, 1864, the proposed Thirteenth
Amendment passed the Senate, 38-6, which was eight votes more
than the needed two-thirds majority. All 30 Republicans voted
in favor; Democrats were divided with four in favor and five
opposed (three were absent); three of the five senators elected
on a Union ticket voted for the measure, one against, and two
were absent; and, the one Unconditional Union senator voted in
the affirmative. By ignoring the questions of enforcement
measures, the role of former Confederate states in the
ratification process, and the more thorny issue of equal rights
under the law, which Senator Sumner’s proposal had raised, the
Thirteenth Amendment was able to attract support from
conservative Republicans and War Democrats.

In the April 23, 1864 issue of Harper’s
Weekly (published April 13), editor George William Curtis
focused his commentary on the speeches given by
four of the opposing senators. That two were from Kentucky and
one from Delaware revealed continuing resistance to emancipation
in those Border States, primarily among Peace Democrats, despite
greater acceptance of it in Missouri, Maryland, and West
Virginia. Curtis concluded that the ultimate adoption of the
amendment would make worthwhile the sacrifice, destruction, and
the death caused by the Civil War.